T-head construction.



W. B. THOMPSON.

' T-HEAB CONSTRUCTION.

APPLICATION FILED JULY 5,1916.

Patented Nov. 6, 1917.

74 B. nompson,

Wm W

WADE B. THOMPSON. OF DETROIT, MICHIGAN.

T-HEAD CONSTRUCTION.

Specification of Letters Patent.

Patented Nov. 6, 1917.

Application filed July 5, 1916. Serial No. 107,722.

To all whom it may concern:

Be it known that I, WADE B. THOMPSON, a citizen of the United States, residing at Detroit, in the county of WVayne and State of Michigan, have invented new and useful Improvements in T-Head Constructions, of which the following is a specification.

This invention relates to a T-head construction and has for its primary object to provide a T-head having the inherent properties of attaching itself to surfaces of certain characteristics.

An object of the invention is the novel manner of associating the magnets and supporting them in the frame so that the greatest amount of magnetic traction can be accomplished.

Besides the above my invention is distinguished in the use of a plurality of permanent magnets having their poles so arranged as to form the straight edge of the T-head.

With these and other objects in view the invention will be better understood from the following detailed description taken in connection with the accompanying drawing, wherein Figure 1 is a top plan view of the head with the plate removed.

Fig. 2 is a cross sectional view thereof.

Fig. 3 is a longitudinal sectional view, and

Fig. 4 is a cross sectional view of a modified form of my invention.

Referring to the drawing the T-head consists of a frame 1 constructed to have a body 2 and three parallel limbs 3, 4 and 5 pro ecting laterally from the body 2. The limb 3 is rigidly connected to the body 6 of the T-square. Filling the spaces between the limb 3 and the limbs 4 and 5 are two sets of permanent bar magnets 7 and 8, each bar magnet 9 of which being formed with a head 10 through all of which with the exception of the end magnet 11 of each set pames a bolt 12 having screw threaded engagement with the magnet 11. From this arrangement it will be seen that all of the magnets of a set are rigidly connected to gether and for the purpose of preventing the grouped bar magnets from movement I provide the securing elements 13 in the form of screws mounted in the frame and having screw threaded engagement with certain of the bar magnets.

To complete my invention I provide plates 14 detachably secured to the frame by the screws 15 and inclosing all of the bar magnets with the exception of the poles thereof that form the straight edge for the head.

If found advantageous in practice the end magnet of each set may have a tongue and groove connection 16 with the limbs of the head.

In the modified form of my invention each bar magnet 17 is in the form of a U so as to have its north and south poles arranged adjacent each other so that the tractive effect may be increased.

At this point I wish to call attention to the fact that I do not care to be limited to the exact arrangement of the poles of the magnet as the polarity of the poles may be identical or reverse depending entirely upon the purpose to which the invention is put.

In this particular showing I have shown a drawing board 18 having secured to its edges a strip 19 of magnetic material, but I wish it to be understood that the T-square may be used directly on iron structures that are being erected.

From the foregoing description taken in connection with the accompanying drawing, it should be apparent that I provide a device which is admirably adapted for the purpose for which it is intended, that the device is simple, durable and eflicient of construction and may be manufactured and sold at a comparatively low cost.

What I claim is 1. In a device of the character described, a series of magnetic elements, a headed screw passing through a hole in said magnetic elements, the far end magnet having a hole therein threaded to engage the screw threads of the screw, a body having a recess therein, and screws engaging holes in said body and screw threaded into certain of the magnetic elements whereby said series of magnetic elements are secured within the recess.

2. In a device of the character described, a body having a recess therein, a magnetic element secured within said recess, a groove formed in said magnetic elements, a tongue formed on said body within said recess and engaging said groove whereby the magnetic element prevents the body from warping.

3. In a device of the character described, a series of magnetic elements, a headed screw passing through holes in said magnetic elements, the far end magnetic element having the hole therein threaded to en age the screw threads of the screw, a' body aving a recess therein, means for securing said magnetic elements within said recess, a groove fm'med in one of Slid magnetic elements, and a tongue formed on said body within said races and engaging said groove whereby said magnetic element prevents the body frmn warping 4. Ina device a series of magnetic elements, a headed screw through holes in said magnetic element, the far end magnetic element of the character described,

having the hole therein threaded to en go the screw threads of the screw, a body av- 1| ing a recess therein, screws engagin said holes in said body and screw th ed in certain of said magnetic elements within said recess, a groove formed in one of said magnetic elements, and a tongue formed on and body within said recess and e said groove whereby the magnetic e ement prevents the body from warping.

In testimony whereof I afix my signature.

WADE B. THOMPSON. 

